The protocol studies of Children's Cancer Study Group are designed and carried out by multidisciplinary study committees culled from group membership. Their purpose is twofold. One is to improve the care and survival of children with leukemia, lymphomas and solid tumors. The second is to conduct scientific research, both clinical and laboratory, which will further investigate the epidemiology, prognostic factors, laboratory findings and cytogenetics of childhood cancer. Phase I-II studies involving new agents are done in patients resistant to conventional therapy. Present studies for acute lymphoblastic leukemia are based on grouping patients by prognostic factors into 5 groups, each of which has its own study plan. Separate protocols have been designed for patients who develop testicular or CNS relapse on therapy. High risk leukemia patients receive either a modified LSA2L2 program or a modified BFM (Berlin, Frankfort, Munich) program. Preliminary studies with these programs show an improved survival in high risk and lymphome syndroma patients. Children with acute non-lymphocytic leukemia (ANLL) are to be treated on a 2 arm chemotherapy induction with appropriate patients going to bone marrow transplant after achieving a complete remission, or continuing on a chemotherapy maintenance arm for 5 drug cycles. Induction chemotherapy will use daunomycin and Ara-C or these drugs plus VP16, thioguanine and dexamethasone. Maintenance therapy will use these drugs plus 5-azacytidine, cyclophosphamide, L-asparaginase and vincristine. A new program for stage III-IV Hodgkin's disease will compare the use of MOPP chemotherapy alternating with ABVD vs. ABVD combined with extended field, low dose radiotherapy. Non-Hodgkin's lymphoma is being treated in 3 studies, one for localized disease, one for disseminated lymphoblastic disease and one for non-lymphoblastic disseminated disease. The osteogenic sarcoma study gives preoperative high dose methotrexate and measures anti-tumor effect. Response of the primary tumor dictates the post-op chemotherapy program.